1. Field of the Invention
The present invention relates to an ink tank and an ink-jet recording apparatus having the same and, more particularly, to an ink tank having a mechanism for resolving abnormal ink discharge from a nozzle and an ink-jet recording apparatus having such an ink tank.
2. Description of the Prior Art
In an ink-jet recording apparatus, the recording ink is supplied to a recording head unit from an ink tank. The ink is discharged from a discharging port of a nozzle of the recording head unit so as to form flying droplets for recording an image on a recording medium. One type of ink tank is separate from a recording head unit and supplies ink to a nozzle through a proper ink supply tube. Another type of ink tank is integrally mounted on the recording head unit.
In an ink-jet recording apparatus, dust or bubbles are sometimes introduced in an ink tank or a communicating portion between the tank and the recording head unit. Since the nozzle of the recording head unit has a small inner diameter of only several tens of microns, when dust and bubbles reach the nozzle of the recording head unit, they become attached to the interior of the nozzle and the like, thereby preventing ink flow. This results in degradation in ink discharge efficiency and poor discharge response with respect to recording signals. In a worst case, dust and bubbles clog the nozzle, thus stopping ink discharge. In addition, when ink discharge is not performed for a long period of time with ink remaining in the ink-jet recording apparatus, ink solids are precipitated, thus causing abnormal ink discharge.
For these reasons, the ink discharging capability of the recording head unit must be recovered. In a conventional method, in order to recover the ink discharging capability, the ink discharging port of the recording head unit is externally capped, and obstacles such as dust are removed from the recording head unit by suction. However, with such a method, an ink discharge recovery device must be provided separately from the recording head unit, and it is difficult to provide a compact recording apparatus. In addition, the ink discharging port and the suction hole of a capping mechanism must be precisely aligned, causing assembly difficulties. Poor alignment also causes damage to the discharging port.
Furthermore, the structure of the apparatus becomes complex, and a low-cost, standard ink-jet recording apparatus cannot be provided.